The goal of this project is to use the solid-state automated microscope (SSAM), developed under NIH grants GM 25107 and GM 27044, and other quantitative image analysis tools to characterize cells exfoliated from normal and malignant urothelium. Such characterization could then be used as the basis for a device for prescreening exfoliated cellular specimens for bladder cancer in high risk populations and for assessing the potential toxic effects of known and suspected chemical carcinogens upon workers in the chemical industry. Using a rat model system, we will apply quantitative image analysis and a variety of cellular cytochemical stains in order to determine which combination gives the best distinct characterization of normal, atypical, and malignant cell populations. The SSAM system would play a key role in this research in that it would permit rapid acquisition of a large number of cell images scanned at high resolution. Specifically a 2.2 mm by 2.2 mm field-of-view can be scanned at 0.6 micron spatial resolution in less than 1.2 seconds. For a well-prepared slide this means that more than 1000 cells per second may be acquired for high-resolution analysis. For all of the stains to be examined the description to be analyzed can include: 1. Nucleus - size, shape, texture (chromatin distribution), stain content. 2. Cytoplasm - size, texture, stain content. Cell enzymatic content and distribution. These descriptions of cells should lead to an incisive quantitative characterization of morphology that correlates with cyto- and histo-pathology.